Su's mother, Heesook, is wearing a beautiful Hanbok, the traditional Korean dress. It is often characterized by vibrant colors and simple lines without pockets. Although the term literally means "Korean clothing", hanbok today often refers specifically to hanbok of the Joseon (Choson) period and is worn as semi-formal or formal wear during traditional festivals and celebrations. Traditionally, a bride's mother wears red on top because red symbolizes passion or good fortune.
Hanbok, Traditional Korean Attire for Celebrations